Yeah I think that very small scale railway shops might have some good wooden fencing - plastic fences or stone walls would be great to have to add some flavour to Empire or Bretonnian forces.
OK, more wacky ideas (but they do work !)
I have green panscrapers and sponge scourers that are pressganged into becomming scenery
the panscrapers are app 3°4mm thick and 10x20cm in size. The material is cutable using scissors and when cunt into slightly irregular strips and fitted to a "stand" works nice as hedges. Smaller garden variety (using trips that are almost square) as well as those found in labyrinths, and when "worked on" a bit to fluff out the strands it makes a very nice boccage style bit too. Ideally suited to create those linear obstacles one would find in the rural areas of empire and bretonia.
The same material is the non foam part of pan scourges, these can be worked the same way, and the spongy material, when suitably cut up and shredded works as foliage for the odd tree.
btw... if you can find access to a wholesaler, check for cake decorations !! not only will it sometimes yield odds and ends, but they usually have plastic palm-trees in large quantities which would work equally well for the odd desert palm as to provide you the basics for a load of jungle terrain